1. Field of the Invention
The present invention relates to a pogo stick with springs having multiple spring rates.
2. Description of Prior Art
Pogo sticks are well-known recreational toys that have been in existence for many years. The pogo stick generally comprises an upper member, which is tubular, having a hand graspable portion at the upper end and having foot-engaging portions at the lower end. Telescopically and slidably fitted into the lower end of the upper member is a lower member having a ground-engaging element at the lower end and with a spring being provided acting axially between the tubular members. Examples of such pogo sticks are described in U.S. Pat. Nos. 2,871,016, 2,929,459, 3,074,715, 3,181,862, 3,427,019, 3,773,320, 4,390,178, 5,087,037, 5,713,819, and shown in U.S. Design Patents 215,552 and 316,280. While these patents describe a variety of pogo sticks, we have found no such devices capable of accommodating weights of 80 to 250 pounds.
Pogo sticks incorporating multiple springs in parallel are known. Two of the patents referred to above, U.S. Pat. Nos. 3,427,019 and 5,713,819, disclose such pogo sticks. However, neither of the pogo sticks described therein utilize springs that have different spring rates.
Pogo sticks having an adjustable spring bias that makes the device more adaptable to individuals of different weights are described in U.S. Pat. Nos. 2,929,459 and 3,733,320. However, the means for adjusting the spring bias does not include multiple springs having different spring rates.
Previously, there was not a pogo stick available that could handle a wide range of weights effectively. The maximum weight range prior to this design was found to be about 80 to 180 pounds. Although this prior art pogo stick was rated to handle this weight range, it was found to be somewhat ineffective. When a lighter person used the pogo stick, the spring would not reach its maximum displacement. On the other hand, a heavier person would reach maximum displacement too easily, thus bottoming out the pogo stick. As stated above, the maximum weight of the user was restricted to 180 pounds. To address these issues, a pogo stick needed to be designed to have an adjustable weight range and to extend the usable maximum weight to 250 pounds and above.
Therefore, it is the primary objective of the present invention to provide a pogo stick that will accommodate a wide range of weights. This objective is attained by an adjustable spring rate pogo stick that incorporates multiple springs with different spring rates in parallel.
In one embodiment, the multiple spring system can produce three different spring rates. The design of this new spring engagement mechanism allows the user to engage one spring (first setting), the other spring (second setting) or both springs simultaneously (third setting). While existing pogo sticks only accommodate weights up to 190 pounds, a preferred pogo stick of the present invention will accommodate weights of about 80 pounds to about 250 pounds.
Another objective is to provide a pogo stick with discrete spring rates achieved by selectively engaging one spring alone or multiple springs.
Another objective of the invention is to provide a pogo stick that can be used for activities such as aerobic workouts, balancing, balance conditioning for athletes, stunts and tricks and family fun.
Another objective of the invention is to provide a pogo stick that can be adjusted to accommodate users of widely different body weights and yet that is light enough to be used effectively.
And yet another objective of the invention is to provide a pogo stick wherein the springs are covered by a safety shield or sleeve to prevent injury in the event of failure.
The foregoing objectives of the present invention are attained by an improved pogo stick, which comprises:
a) a top brace;
b) a handle fastened to the top brace;
c) a bottom brace;
d) frame members that form a part of said handle and that are fastened to the top and bottom braces;
e) an elastic member that consists of multiple compression springs having different spring rates and that slidably surround the frame members and are compressible between the top brace and the bottom brace;
f) a center shaft that is parallel to the frame members and in slidable relationship to said top and bottom braces; and
g) engagement means that are in communication with the end of the springs nearest the bottom brace and that selectively allows only one or multiple springs to be compressed simultaneously, thereby providing three or more different spring settings.
In a preferred embodiment, the foregoing objectives of the present invention are attained by an improved pogo stick, which comprises:
a) a top brace;
b) a handle fastened to the top brace;
c) a bottom brace;
d) a pair of frame members that form a part of said handle and that are fastened to the top and bottom braces;
e) an elastic member that consists of first and second compression springs having different spring rates and that slidably surround the frame members and are compressible between the top brace and the bottom brace;
f) a center shaft that is parallel to the frame members and in slidable relationship to said top and bottom braces; and
g) engagement means that are in communication with the end of the springs nearest the bottom brace and that selectively allows only the first spring or the second spring or both of them to be compressed simultaneously, there by providing three different spring settings.